Method and apparatus for storing and presenting visual and audible information to an individual

ABSTRACT

A method and apparatus for storing and presenting visual and audible information to an individual. Audio source signals from a stereophonic audio source are processed by a microcontroller-controlled circuit that also receives commands from a programmer. The programmer commands cause the generation of pulsed low audio frequency control signals for each channel. The audio source signals are processed so that their frequencies are translated above the low audio frequency range of the pulsed control signals and inverted. The pulsed control signals are then added to the corresponding processed audio source signals to produce two combined audio signals which are then recorded on a compact disc. To replay the recorded information, the recorded combined audio signals are read from the compact disc. The pulsed control signals and processed audio source signals are separated by filtering and the processed audio source signals are reprocessed to recreate the original audio source signals. The pulsed control signals drive separate channel LED displays built into a headset visor and the audio source signals are concurrently played through speakers in the headset. Also disclosed is a method for using the apparatus so that the individual can learn information.

This application is a continuation of application Ser. No. 08/150,354,filed Oct. 29, 1993 abandoned, the benefit of the filing dates of whichare hereby claimed under 35 USC 120.

TECHNICAL FIELD

The present invention relates to systems for presenting information toan individual, and more particularly, to a method and apparatus forstoring and presenting visual and audible information to an individual.

BACKGROUND OF THE INVENTION

As electronics has advanced With improved microprocessors and otherintegrated circuit technology, improved methods of communication andentertainment have become available. For example, advanced electronicsare largely responsible for the advent of such entertainment systems ascompact disc (CD) technology. CD technology depends heavily uponadvanced signal processing techniques to both encode information whichis to be stored on a CD as well as to decode and retrieve the recordedinformation. CDs have the obvious advantage of being capable of storinglarge quantities of digitized information securely and transportably aswell as conveniently.

An important use of CD technology is in the entertainment field.Certainly CDs have become the predominant form in which music is sold tothe consuming public. Therefore, the public has ready access to CDplayers. While such CDs store a great deal of music information forlistening, it is possible to add other entertainment value to CDs. Onepossible way to add entertainment value is to provide visualentertainment which is coordinated with the audible entertainment. Whileit is well-known to provide visual-audible information coordination inmotion pictures and video tapes, where the audible and visual tracks arekept separate, it is not well-known to do so in such a way that theaudible and visual information are stored together on an audible track,such as on a CD.

There are applications which have the need to put the information on aCD in such a way that only qualified users can retrieve the information.In this way, quality of the information can be assured and unqualifiedusers will be unable to access the information. While such securitymeasures have been proposed in the past, it is particularly convenientto be able to apply the security measures in a simple way which needonly be used to transform the information in the audio frequency rangebefore it is encoded on the CD.

Research conducted by Dr. Georgi Lozanov, Dr. Jane Bancroft and others,has shown that students can increase their rate of learning and memoryretention by as much as 300% when certain factors exist. These factorsinclude: 1) the learning experience is interactive; 2) a specificmusical formula is incorporated into the learning experience; and 3) thestudent is in a relaxed state of mind.

The research concerning accelerated learning is described in:"Suggestology and Outlines of Suggestopedy," by G. Lozanov, NewYork:Gordon and Breach, 1978; "Suggestology and Suggestopaedia: TheTheory of the Lozanov Method," by W. J. Bancroft, Journal of S.A.L.T.,Vol. 1, No. 4 (Winter 1976); "Suggestive-Accelerated Learning:Adaptations of the Lozanov Method," by O. Caskey and M. Flake, TexasTech. University, 1976; and "Toward a Theory for Research of Learning inan Altered State of Consciousness," by R. Benitez-Bordon and D. P.McClure, University of Iowa, 1974. It has been determined that musicwith a tempo of 60-70 beats per minute is most effective, and that musicthat is more tonal and less dissonant is preferable.

The research concerning inducing a relaxed state of mind usingcontrolled patterns of repetitive light and sound frequencies isdescribed in: "Brain Wave Synchronization (Photo-Stimulation) with theShealy Relaxmate," by C. Shealy, Shealy Institute, 1990; "Photic Drivingand Altered States of Consciousness: An Exploratory Study," by J.Glicksohn, Imagination, Cognition and Personality, 6, 167-182, 1986; and"The Effects of Photic Stimulation and Private Self-Consciousness on theComplexity of Visual Imagination Imagery," by A. Richardson and F.McAndrew, British Journal of Psychology, 81, 381-394, 1990.

SUMMARY OF THE INVENTION

According to one aspect, the invention is a method for recording one ormore audio signals and one or more control signals onto a storage mediumhaving a frequency response in a response frequency range. The one ormore audio signals and the one or more control signals are recorded forsubsequent retrieval from the storage medium. The method comprises thesteps of a) transforming at least one of the one or more audio signalsand at least one of the one or more control signals to produce acomposite transformed audio signal occupying at least two distinct audiofrequency ranges, the at least two distinct audio frequency rangesfalling within the response frequency range of the storage medium, andb) recording the composite transformed audio signal on the storagemedium.

According to another aspect, the invention is a method for retrieving anaudio signal from an audio signal stored on a storage medium. The storedaudio signal includes component audio signals occupying two distinctfrequency ranges. The method comprises the steps of a) separating thecomponent audio signal stored in one of the two distinct frequencyranges from the component audio signal stored in the other of the twodistinct frequency ranges, and b) transforming the frequencies of thecomponent audio signal occupying at least one of the two distinctfrequency ranges to a playback frequency range, the playback frequencyrange being different from the one frequency range.

According to a still further aspect, the invention is an apparatus forrecording an audio signal and a control signal onto a storage medium,for subsequent retrieval from the storage medium. The apparatuscomprises means for transforming the audio signal and the control signalto produce a transformed composite audio signal occupying two distinctaudio frequency ranges, the two distinct audio frequency ranges bothfalling within an audio response frequency range of the storage medium,and means for recording the transformed audio signal onto the storagemedium.

According to yet another aspect, the invention is an apparatus forretrieving two audio signals from an audio signal stored on an opticalstorage medium, the stored audio signal occupying two distinct frequencyranges. The apparatus comprises means for transforming the stored audiosignal into an analog signal occupying the two distinct frequencyranges, means for separating the audio signals stored in one of the twodistinct frequency ranges from the audio signals stored in the other ofthe two distinct frequency ranges, and means for transforming thefrequencies of the audio signals occupying at least one of the twodistinct frequency ranges to a playback frequency range, the playbackfrequency range being different from the one frequency range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the preferred embodiment of a firstaspect of the present invention.

FIG. 2 is a schematic diagram of the preferred embodiment of a secondaspect of the present invention.

FIG. 3 is a schematic diagram of the signal processing in accordancewith a preferred embodiment of the first aspect of the presentinvention.

FIG. 4 is a block diagram of the signal processing in accordance withthe preferred embodiment of the first aspect of the present invention.

FIG. 5 is a schematic diagram of the signal processing in accordancewith a preferred embodiment of the second aspect of the presentinvention.

FIG. 6 is a block diagram of the signal processing in accordance withthe preferred embodiment of the second aspect of the present invention.

FIG. 7 is a flow chart of a method for use in accordance with thepreferred embodiment of the second aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic diagram of the preferred embodiment of a firstaspect of the present invention. A record apparatus 30 includes aprocessing circuit 32 that receives inputs such as commands from aprogrammer using a terminal 34 (including data and program memories anda keyboard), through the cable 36, and, in response to the inputs,produces visible displays on the display 38, through the cable 40, andprocesses signals that the record apparatus 30 receives. The recordapparatus 30 receives audio signals through cables 42L and 42R from anaudio source 44. In the case that the audio source 44 is a stereo sourceof audio signals, the cable 42L carries a left channel signal and thecable 42R carries a right channel signal.

The processing circuit 32 includes a microcontroller 45 which controlsvarious functions of the circuit 32, including receiving andinterpreting the commands from the terminal 34. The microcontroller 45includes an Intel 80C51FA microprocessor and its associated supportcomponents. These include a 64 kilobyte flash memory for code storage,plus a 32 kilobyte static RAM for LED tone program storage. Thecircuitry 32 also includes a transparent latch used to hold thelow-order address to the memory devices during the data portion of a buscycle, as the microcontroller multiplexes address and data on theselow-order address lines.

Also in the microcontroller 45 is a 75155 RS-232 driver/receiver (U15).This device provides interface to standard RS-232 levels for serialcommunications to the terminal 34. The 80C51's internal UART is used toperform serial data transfer. The serial data format is 9600 baudasynchronous data with eight data bits and one stop bit. No parity isemployed.

The record apparatus 30 produces output audio signals on the cables 46Land 46R. In the case that the audio source 44 is a stereo source ofaudio signals, the cable 46L carries a left channel signal and the cable46R carries a right channel signal. The audio signals in the cables 46Land 46R are passed to a compact disk recorder 48 which records the audiosignals on a compact disk. Alternatively, the compact disk recorder 48could be replaced by another audio signal recorder, such as a cassetterecorder.

If desired, a programmer using the record apparatus 30 can monitor theperformance of the recording process by transmitting the audio signalsin the cables 46L and 46R by connecting first ends of cables 50L and 50Rrespectively to the cables 46L and 46R and connecting second ends of thecables 50L and 50R to a playback apparatus 52. The playback apparatus 52is preferably built into the headset 58, although, for clarity, it isshown outside the headset 58 in FIG. 2. As will be discussedsubsequently, the playback apparatus 52 processes the audio signals inthe cables 46L and 46R to reproduce the original source audio materialand to test other signals that can be generated by the programmer, aswill also be discussed subsequently.

In the preferred embodiment, the playback apparatus 52 generates fouraudio signals. Two of the signals are reproductions of the left andright channel signals that are generated on the cables 42L and 42R onthe audio source 44. The reproduced left channel signal is transmittedthrough one line in the cable 54L and the reproduced right channelsignal is transmitted through one line in the cable 54R. The reproducedleft and right channel signals are played audibly to the programmerthrough speakers 55L and 55R in the headset 58. Another line in thecable 54L carries an audio control signal that leads to a light-emittingdiode (LED) display 56L on the left-hand side of a visor 59, which isshaped to be worn by a person, such as the programmer. Another line inthe cable 54R carries an audio control signal that leads to alight-emitting diode (LED) display 56R on the right-hand side of thevisor 59. The audio control signals cause the LED displays 56L and 56Rto turn on and off as programmed by the programmer.

The programmer programs the record apparatus 30 by means of aconventional command set which allows control over the audio encoded LEDinformation that is played on the headset 58. The record apparatus 30 iscapable of storing a LED-tone program in a conventional memory, thenmixing that program with an audio sound track as described above. Eachcommand consists of a string of one or more ASCII characters followed bya carriage return.

The record apparatus 30 will respond to unrecognized or incorrectlyformatted commands with a question mark (?).

The LED-tone program is loaded into the record apparatus 30 by thetechnician using a series of (S)et commands, each command describing onebehavior. Each behavior consists of a frequency, phase and duration, andthe entire program consists of a sequence of individual behaviors.

The (S)et command has the form:

S P FF DDDD,

where P is a phase code, explained below, FF is the strobe frequency,from 0 to 15 Hz and DDDD is the duration in seconds from 1 to 9999. Thephase code is defined as follows:

P=0--Left and right LEDs strobe in phase.

P=1--Left and right LEDs strobe out of phase.

Note that the command must be formatted precisely as shown, with onedigit for phase, two digits for frequency and four digits for duration.The spaces separating the fields in the command are optional, but arerecommended for readability.

Example:

    ______________________________________                                        S 0 03 0010                                                                   S 1 05 0020                                                                   S 0 00 0005                                                                   S 1 07 0010                                                                   S 0 09 0010                                                                   ______________________________________                                    

When this set of behaviors is programmed and executed on the recordapparatus 30, it will result in a master which, when played back throughthe digital headset, will cause the LEDs to strobe in phase at 3 Hz for10 seconds, then out of phase at 5 Hz for 20 seconds, then become dark(0 Hz) for five seconds, then strobe out of phase at 7 Hz for 10seconds, then in phase at 9 Hz for 10 seconds.

The record apparatus 30 will support programs as long as 5000 lines;that is, a sequence of 5000 different behaviors.

Before beginning a new (S)et sequence, the technician must issue the(C)lear command to the unit to clear any existing program informationcurrently in its buffer. This condition will also be attained byremoving power from the record apparatus 30. The format of the (C)learcommand is:

C.

The sequence of (S)et commands is then entered, followed by the (G)ocommand. Upon receipt of the (G)o command, the record apparatus 30 willbegin mixing the programmed LED behavior with the scrambled audio assoon as audio is detected at the record apparatus 30 input port. Theformat of the (G)o command is:

G.

Entire programs, including the (C)lear and (G)o commands, can be storedin a computer file and downloaded to the record apparatus 30 via aterminal program. An example of such a program would be:

    ______________________________________                                                    C                                                                             S 0 10 0030                                                                   S 1 10 0030                                                                   S 0 12 0090                                                                   S 1 12 0090                                                                   S 1 13 0120                                                                   S 1 14 0120                                                                   S 1 15 0120                                                                   G                                                                 ______________________________________                                    

Having received this entire sequence from the technician, eitherdirectly or from a file, the record apparatus 30 will begin mixing theprogram as soon as audio is detected on the record apparatus 30 input.

It is recommended that program information be generated in file form,and loaded as a unit to the record apparatus 30. This reduces theopportunity for error, and allows the technician the ability to edit theprogram before loading it, and to save the program for future reference.

FIG. 2 is a schematic diagram of the preferred embodiment of a secondaspect of the present invention. A compact disc which has been recordedin accordance with the record apparatus 30 described in FIG. 1 is placedinto a compact disc player 70. The compact disc player 70 produces leftand right channel audio signals on cables 72L and 72R, respectively. Theplayback apparatus 52 described in FIG. 1 receives and processes theleft and right channel audio signals to generate four audio signals. Twoof the signals are reproductions of the left and right channel signalsthat were generated on the cables 42L and 42R (in FIG. 1) on the audiosource 44 when the compact disc was recorded. The reproduced leftchannel signal is transmitted through one line in the cable 54L and thereproduced right channel signal is transmitted through one line in thecable 54R. The reproduced left and right channel signals are playedaudibly to the user through speakers 55L and 55R in the headset 58.Another line in the cable 54L carries the audio control signal thatleads to the light-emitting diode (LED) display 56L on the left-handside of the visor 59, which is worn by the user. Another line in thecable 54R carries the audio control signal that leads to the LED display56R on the right-hand side of the visor 59. The audio control signalscause the LED displays 56L and 56R to turn on and off in conjunctionwith the audio signals produced by the audio source 44, as processed bythe record apparatus 30.

FIG. 3 is a schematic diagram of the signal processing in accordancewith a preferred embodiment of the first aspect of the presentinvention. FIG. 3 shows schematically how two audio signals 80 and 82are combined by the preferred embodiment to produce the desired audiosignals for recording. The audio signal 80 is typically one channel of astereo signal, such as a stereo music signal. The audio signal 82typically includes a series of pulses, each pulse comprising 5 cycles ofa 200 Hz tone. Each pulse in the audio signal 82 causes the LED display56 corresponding to that channel to light for a specific period of time,typically about 15 milliseconds. The pulses in a given channel arerepeated at a repetition frequency, also determined by the programmer.The 200 Hz tones are filtered in the record apparatus 30 prior to mixingto remove any higher-order harmonics which might interfere with theaudio sound track above 1384 Hz.

The pulses in both channels occur at the same repetition frequency,although the programmer can cause the pulses in one channel to be eitherin phase or 180 degrees out of phase with respect to the pulses in theother channel. Thus, the programmer determines the flashing frequency ofthe LED displays 56L and 56R and also whether the LED displays 56L and56R flash synchronously, or out of phase. The time durations and thefrequencies in the audio signal 82 are established by the programmer, asgenerally described in connection with FIG. 1.

The audio signal 80 has a spectral content as shown by the spectrum 86.The spectrum 86 shows that the audio signal 80 typically containsfrequencies in the range of f₀ =0 Hz to f₂ =15 kHz. Similarly, the audiosignal 82 has a spectral content as shown by the spectrum 88. Thespectrum 88 shows that the audio signal 82 typically contains discretefrequencies in the range of f₀ 0 Hz to f₁ 200 Hz. As will be describedsubsequently, the two audio signals 80 and 82, having the spectra 86 and88 are combined to produce an audio signal having a spectrum 90 rangingfrom f₀ to f_(h), where f₀ <f₁ <f₂ <f_(h). An audio signal having thespectrum 90 would have only the slightest resemblance to the audiosignal 80. Accordingly, the audio signal having the spectrum 90 must befurther processed to produce a signal that can be replayed on a CDplayer, such as CD player 70.

The spectrum 90 is related to the spectra 86 and 88 as follows. If thespectrum 86 is reversed in frequency and shifted upward by 1384 Hz, theresult would be the high frequency portion of the spectrum 90. The lowfrequency portion of the spectrum 90 is the same as the spectrum 88.

FIG. 4 is a block diagram of the signal processing in accordance withthe preferred embodiment of the first aspect of the present invention.The signals processing shown in FIG. 4 will accomplish thetransformation of the spectra 86 and 88 in FIG. 3 to produce thespectrum 90. The audio signal from one channel of a stereo source, suchas audio source 44 in FIG. 1 and having the spectrum, is received by therecord apparatus 30 and mixed with a 16,384 kHz signal in a conventionaldoubly-balanced mixer 100. (The mixer 100 is similar to the mixer 134,which is discussed subsequently.) The result is an audio signal 102having a spectrum 104 which is a mirror image reflection of the spectrum86 about the 16,384 kHz frequency, after the spectrum 86 has beenshifted upward by 16.384 kHz. The upper sideband portion of the spectrum104 has the same shape as the original spectrum 86. The lower sidebandportion of the spectrum 104 has the mirror image of the originalspectrum 86. The spectrum 104 has no desired signal power below 1384 Hz,and a negligible amount exists in practice.

Next, the signal 102 is filtered in a filter 106 to produce an audiosignal 108 whose spectrum corresponds to isolating the lower sideband ofthe spectrum 104. This is accomplished by suppressing the upper sidebandof the spectrum 104. The filter 106 is a low-pass filter exhibiting a4th-order Chebyshev response with a pass-band ripple of 0.5 dB. Next,the audio signal having the spectrum 88 is added to the audio signal 108in a conventional analog summer 110 to produce the desired audio signal112 which is output by the recording apparatus 30. The audio signalhaving the spectrum 88 is generated in response to control signalsentered by the programmer, as shown in FIG. 1. The signals include5-cycle 200 Hz tone bursts at a programmable repetition rate determinedby the programmer. Their structure will be discussed subsequently.

The signal produced by each channel of the audio source 44 is processedseparately, so that the two output audio signals produced by therecording apparatus 30 correspond to the two channels of the audiosource 44. Accordingly, if the cable 42 in FIG. 4 is cable 42L, theaudio signal 112 is audio signal 112L.

FIG. 5 is a schematic diagram of the signal processing in accordancewith a preferred embodiment of the second aspect of the presentinvention. The signal 112, having a corresponding spectrum 90, isprocessed to separate its lower frequency portion 114 from its upperfrequency portion 116. The lower frequency portion 114 can be separatedby filtering through a band pass filter to reproduce the spectrum 88.The upper frequency portion 116 of the spectrum is also furtherprocessed to reproduce the signal having the spectrum 86.

FIG. 6 is a block diagram of the signal processing in accordance withthe preferred embodiment of the second aspect of the present invention.The signal 112 is passed through a conventional bandpass filter 130 toextract the LED control signals. The LED control signals are thenprocessed by an LED tone detector 131 which conventionally generates ashort pulse of a duration of about 15 milliseconds in response to eachpulse in the LED control signal. The LED tone detector 131 performs apeak-detection and comparison on the LED control signals. The LEDcontrol signals are used to trigger a monostable circuit which producesan output pulse in response to each pulse in the LED control signal. Themonostable circuit pulses the base of a LED drive transistor in theappropriate LED display 56, which drives the LED very briefly(approximately 15 ms), but with a very high current (approximately 100mA). This results in a LED pulse which is perceived as being verybright, but a low average power consumption. LED drive holdingcapacitors are charged at a low rate when the LEDs are off. When theLEDs are strobed, current is drawn through low-value resistors,discharging the holding capacitors through the LEDs.

The signal 112 is also passed through a high pass filter 132 to separatethe upper frequency portion 116 of the spectrum from the lower frequencyportion 114. The high pass filter 132 is a 5th order Chebyshev filter at1384 Hz. The resultant signal 116 is then mixed in a doubly-balancedmixer 134 with a square wave signal at 16,384 kHz to produce a signalhaving a spectrum with two portions. The lower frequency portion 136lies between 0 Hz and 15000 Hz and the upper frequency portion 138 liesbetween 17768 Hz and 32768 Hz. The upper frequency portion 138 isfiltered out by a conventional low pass filter 140 to produce an audiosignal 142 having a spectrum 144 that is substantially the same as theoriginal signal spectrum 86 (see FIG. 3).

FIG. 7 is a flow chart of a method for use in accordance with thepreferred embodiment of the second aspect of the present invention. Inapplication, the preferred embodiment of the second aspect of thepresent invention can be used to enhance and accelerate learning in astudent. In the method for use, the student is provided with an audibledescription of the lesson the student is to learn, and provided with acontext for the lesson (block 150). Next, the method enters an activelearning session (block 152). In this session, the student is providedwith visual printed material, and with instructions for use of thevisual printed material. Next, the student is prompted by a teacher oran automated system to recite or repeat specific parts from the visualprinted material. Following this, the student is prompted by a teacheror an automated system to answer audible questions from multiplepossible responses.

The method for using continues into a passive learning session (block154). In the passive learning session, a condensation of the activelearning session is audibly played back to the student, along withselected music which is played concurrently with flashing lightpatterns. Preferably, the condensed active learning session and selectedmusic are mixed together to produce an audio track (or source Signal)that can be recorded on a CD, and control signals to control the rateand phase of the flashing lights produce a control signal that can alsobe recorded on the CD. Both of these processes are described in detailabove. The method for using next enters a verification stage (block156), in which the selected music played during the passive learningsession is replayed while the student is asked to respond to questionsdesigned to cause recall of information in the visual printed material.The replay of the selected music hastens the learning of theinformation, since the music accompanied the information during thepassive learning session. Finally, in a wrap session (block 158), thestudent is provided with a synopsis of the lesson. If desired, thestudent can then be taken to block 150 again, in order to learn anotherlesson. Otherwise the learning session can be terminated.

While specific embodiments of various aspects of the present inventionhave been disclosed in the foregoing detailed description, those skilledin the art would appreciate modifications of the described embodimentswhich are within the scope of the present invention. Accordingly, thepresent invention is limited only by the following claims.

I claim:
 1. A method for recording for subsequent retrieval at least oneaudio signal and at least one control signal onto a storage mediumhaving a frequency response range from a low frequency f₀ to a highfrequency f_(h), wherein the at least one control signal has a frequencyrange of f₀ to f₁, and the at least one audio signal has a frequencyrange from f₀ to f₂, where f₀ <f₁ <f₂ <f_(h), the method comprisingsteps of:a) transforming the at least one audio signal and the at leastone control signal to produce a composite transformed signal occupyingat least two distinct audio frequency ranges that both fall within theresponse frequency range f₀ to f_(h) of the storage medium, said atleast two distinct audio frequency ranges include a lower compositetransformed frequency range from f₀ to f₁, and an upper compositetransformed frequency range from a value>f₁ to f_(h) ; b) recording thecomposite transformed audio signal on the storage medium; and c) thestep of transforming the at least one audio signal causing the frequencyrange occupied by the transformed at least one audio signal to beshifted and inverted, so that the frequency f₀ of the at least one audiosignal is transformed to approach a high end f_(h) of the uppercomposite transformed frequency range and the frequency f₂ of the atleast one audio signal is transformed to approach said value>f₁ at a lowend of the lower composite transformed frequency range.
 2. The method ofclaim 1, wherein the at least one control signal has a relativelynarrowband compared to the least one audio signal, and step a) furtherincluding transforming the narrowband control signal into a transformednarrowband control signal occupying said lower composite transformedfrequency range and transforming the at least one audio signal into atransformed analog signal occupying said upper composite transformedfrequency range that is wider than said lower composite transformedfrequency range, the highest frequency of the transformed narrowbandcontrol signal being lower than the lowest frequency of the transformedanalog signal.
 3. The method of claim 2, wherein the narrowband controlsignal has a narrowband control signal frequency range and thetransformed narrowband control signal frequency range is identical tothe narrowband control signal frequency range.
 4. The method of claim 3,wherein the transformed analog signal frequency range is equal in widthto the frequency range of the audio signal.
 5. An apparatus forrecording an audio signal and a control signal onto a storage medium,for subsequent retrieval from the storage medium, the apparatuscomprising:means for transforming the audio signal and the controlsignal to produce a composite transformed signal occupying at leastfirst and second distinct audio frequency ranges, the at least first andsecond distinct audio frequency ranges falling within an audio responsefrequency range of the storage medium; and means for recording thetransformed signal onto the storage medium wherein the control signaloccupies a frequency range from a lower frequency limit f₀ to arelatively higher frequency limit f₁, and the signal occupies afrequency range from a lower frequency limit f₀ to a higher frequencylimit f₂ and the composite transformed signal occupies a transformedfrequency range from a lower transformed frequency f₀ to a hightransformed frequency limit f_(h), where f₀ <f₁ <f₂ f_(h), the means fortransforming the audio signal further causing the frequency rangeoccupied by the audio signal to be inverted and shifted, so that thelower frequency limit f₀ of the audio signal is transformed into thesecond distinct audio frequency range of the composite transformedsignal approaching f_(h) and the high frequency limit f₂ of the audiosignal is transformed so as to reside at a lower limit of said seconddistinct audio frequency range and above frequency f₁.
 6. The apparatusof claim 5, wherein the control signal is a relatively narrowbandcompared to said audio signal, the means for transforming furthertransforming the narrowband control signal into a transformed narrowbandcontrol signal occupying said first distinct audio frequency range andtransforming the audio signal into a transformed analog signal frequencyoccupying said second distinct range that is relatively wider than thetransformed narrowband control signal frequency range, the highestfrequency f₁ in the transformed narrowband control signal frequencyrange being lower than the lowest frequency in the transformed analogsignal frequency range.
 7. The apparatus of claim 6, wherein thenarrowband control signal has a narrowband control signal frequencyrange and the transformed narrowband control signal frequency range isidentical to the narrowband control signal frequency range.
 8. Theapparatus of claim 7, wherein the transformed analog signal frequencyrange is equal in width to the frequency range of the audio signal. 9.An apparatus for recording an audio signal and a second signal into astorage medium, for subsequent retrieval from the storage medium theapparatus comprising:a signal processor to transform the audio signaland the second signal to produce a transformed signal occupying firstand second distinct audio frequency ranges both falling within an audioresponse frequency range of the storage medium; and a recorder to recordthe transformed signal on the storage medium wherein the second signaloccupies a frequency range from a lower frequency f₀ to a higherfrequency f₁, the audio signal occupies a frequency range from saidlower frequency f₀ to an even high frequency f₂, and the transformedsignal occupies a transformed frequency range from a lower transformedfrequency f₀ to an upper transformed frequency f_(h) where f₀ <f₁ <f₂<f_(h), the signal processor further causing the frequency rangeoccupied by the audio signal to be inverted and shifted, so that thelower frequency f₀ of the audio signal is transformed into the uppertransformed frequency f_(h) and the frequency f₂ of the audio signal istransformed into a relatively lower portion of said second distinctaudio frequency range of said transformed signal above said frequencyf₁.
 10. The apparatus of claim 9, wherein the second signal is anarrowband control signal and the audio signal is an analog signal, thesignal processor further transforming the narrowband control signal intoa transformed narrowband control signal frequency range and transformingthe analog signal into a transformed analog signal frequency range thatis relatively wider than the transformed narrowband control signalfrequency range, the highest frequency in the transformed narrowbandcontrol signal frequency range being lower than the lowest frequency inthe transformed analog signal frequency range.
 11. The apparatus ofclaim 10, wherein the narrowband control signal has a narrowband controlsignal frequency range and the transformed narrowband control signalfrequency range is identical to the narrowband control signal frequencyrange.
 12. The apparatus of claim 11, wherein the transformed analogsignal frequency range is equal in width to the frequency range of theaudio signal.